network_freebsd_sendfile does not handle EAGAIN or EINTR on file chunks (patch)

[petopeto]

If a single call is writing a memory chunk followed by a file chunk, the memory chunk may fill the kernel buffer, and the file chunk's sendfile() will return EAGAIN. If no data was written from the chunk at all, the "r == 0" case would return with -2. Work around by disabling the "r == 0" case for non-fatal sendfile() errors.

This was causing pages to not display images randomly. It wouldn't show up as an error in FF, because the headers in the memory chunk would be received, and it would see the image as a 0-byte successful file.

Also, EINTR is not handled. If the writev case needs this, the sendfile one probably does, too.

[stbuehler]

Fixed in [2256]